Trailer step assembly

ABSTRACT

A trailer, retractable stair assembly, and method of operating same is provided. The trailer includes a frame that defines an interior cavity. A retractable stair assembly is movable between a stowed position in which the retractable stair assembly is positioned within the interior cavity and a deployed position in which the retractable stair assembly extends out of the trailer frame to establish a plurality of steps out of the trailer to an egress surface.

RELATED APPLICATIONS

This is a continuation application of U.S. patent application Ser. No.16/702,710 filed Dec. 4, 2019 for a “Trailer Step Assembly” (now U.S.Pat. No. ______), which was a continuation application of U.S. patentapplication Ser. No. 16/514,306 filed Jul. 17, 2019, for a “Trailer StepAssembly” (now U.S. Pat. No. 10,518,708) and U.S. patent applicationSer. No. 16/266,362 filed Feb. 4, 2019, for a “Trailer Step Assembly”(now U.S. Pat. No. 10,525,891), each of which is hereby incorporated byreference in their entireties.

TECHNICAL FIELD

This disclosure relates generally to trailers; in particular, thisdisclosure relates to a retractable stair assembly for a trailer.

BACKGROUND

Trailers, motor homes, and like vehicles have become very popular. Thesetypes of vehicles have a floor level elevated at a considerable distanceabove ground level. This makes stairs or some other transitional surfacenecessary.

There is a variety of existing stair designs for these types ofvehicles. Some stairs have fixed steps and are deployed by placing thestairs adjacent to the vehicle when it is parked; however, these fixedstairs must be placed into a storage space when the vehicle istraveling. Others stair assemblies are retractable. Retractable stairscan be extended to a deployed position that provides a transitionalsurface out of the vehicle and then retracted out of way when not inuse.

FIGS. 1 and 2 illustrate an existing retractable stair assembly 10 for atrailer 12. The retractable stair assembly 10 is movable between adeployed position (FIG. 1) and a stowed position (FIG. 2). As istypical, the retractable stair assembly 10 is installed underneath thetrailer 12. Unfortunately, in this position, the retractable stairassembly 10 is exposed to the elements, such as rain, snow, road saltand/or dirt. Additionally, the retractable stair assembly 10 isvulnerable to being damaged, such as due to lack of clearance underneaththe trailer 12 on a steep slope or rocks kicking up underneath thetrailer 12 as it travels.

When the retractable stair assembly 10 is deployed, there is a slideassembly 14 that moves the steps 16 and step platform 18 (the first stepdown from the floor level of the trailer) out from its stowed positionunderneath the trailer 12. The floor level of the trailer 12 isrepresented by line 13.

Since the retractable stair assembly 10 is stowed underneath the trailer12, the retractable stair assembly 10 includes a lift mechanism 20 toelevate the step platform 18 as the retractable stair assembly 10 isbeing deployed. When in the stowed position, the step platform 18collapses downward to align with the slide assembly 14 underneath thetrailer 12; however, when the step platform 18 is deployed, it elevatesvia the lift mechanism 20. Without this lift mechanism 20, the stepplatform 18 would be positioned too low from the floor level 13 andwould be a potentially dangerous transition.

The step platform's 18 elevated height in the deployed position (FIG. 1)compared to the collapsed position (FIG. 2) is illustrated by comparingthe longitudinal axis of the slide assembly 14 (defined by line 22) withthe longitudinal axis of the step platform 18 (defined by line 24) inthe deployed position. The lift mechanism 20 and elevation of the stepplatform 18 during deployment increases complexity and manufacturingcost of the retractable stair assembly 10. Moreover, this designnecessitates a fixed length of the step platform 18 that cannot beadjusted.

As seen in FIG. 2, the retractable stair assembly 10 is underneath thetrailer frame structure 26. As discussed above, this placement of theretractable stair assembly 10 has several downsides, including exposureto the elements and vulnerability to being damaged. Additionally, asdiscussed, this position underneath the trailer requires the liftmechanism 20 to elevate the step platform 18 during deployment so thefirst step out of the trailer 12 is not down too far, which would bepotentially dangerous.

Therefore, a need exists that overcomes one or more of the disadvantagesof present retractable stair assemblies.

SUMMARY

According to one aspect, this disclosure provides a trailer with aretractable stair assembly. The trailer includes a trailer frame with aframe platform and at least one structural beam extending from the frameplatform. The frame platform and the structural beam define an interiorcavity. The trailer also includes a retractable stair assembly movablebetween a stowed position in which the retractable stair assembly ispositioned within the interior cavity of the trailer frame and adeployed position in which the retractable stair assembly extends out ofthe trailer frame to establish a plurality of steps out of the trailerto an egress surface.

According to another aspect, this disclosure provides a retractablestair assembly for a trailer having an interior cavity defined by atrailer frame. The retractable stair assembly includes a slide assembly,a platform, and a plurality of steps. The platform is connected with theslide assembly such that the platform is slidably movable between astowed position and a deployed position. The plurality of steps areoperatively connected with the platform. The platform moves between thestowed position and the deployed position along a single plane.

According to a further aspect, this disclosure provides a method ofmoving a retractable trailer stair assembly between a stowed positionand a deployed position. The method includes the steps of: (i) providinga retractable stair assembly in a stowed position in which theretractable stair assembly is disposed within an interior cavity of atrailer frame; (ii) moving the retractable stair assembly from thestowed position to a deployed position extending out of the trailerframe, wherein the retractable stair assembly includes a platform and aplurality of steps configured to define a set of steps out of a trailerto an egress surface in the deployed position. In some embodiments, theplatform is linearly movable between the stowed position and thedeployed position.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be described hereafter with reference to theattached drawings which are given as non-limiting examples only, inwhich:

FIG. 1 is left side, perspective view of a prior art retractable trailerstair assembly in a deployed position;

FIG. 2 is a front perspective view of the prior art retractable trailerstair assembly shown in FIG. 1 in a stowed position;

FIG. 3 is a right side, perspective view of an example retractabletrailer stair assembly in a deployed position according to an embodimentof the present disclosure;

FIGS. 4A-4D are a series of progression views showing left side,perspective views of the example retractable trailer stair assemblyshown in FIG. 3 moving from a stowed position to a deployed position;

FIG. 5 is a left side, perspective view of the example retractabletrailer stair assembly installed in a trailer frame without the trailerbody;

FIG. 6 is a left side, perspective view of the example retractabletrailer stair assembly shown in FIG. 5 in a deployed position; and

FIG. 7 is a front, perspective view of the example retractable trailerstair assembly shown in FIG. 5 in a deployed position.

Corresponding reference characters indicate corresponding partsthroughout the several views. The components in the figures are notnecessarily to scale, emphasis instead being placed upon illustratingthe principals of the invention. The exemplification set out hereinillustrates embodiments of the invention, and such exemplification isnot to be construed as limiting the scope of the invention in anymanner.

DETAILED DESCRIPTION OF THE DRAWINGS

While the concepts of the present disclosure are susceptible to variousmodifications and alternative forms, specific exemplary embodimentsthereof have been shown by way of example in the drawings and willherein be described in detail. It should be understood, however, thatthere is no intent to limit the concepts of the present disclosure tothe particular forms disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the disclosure.

This disclosure relates to a retractable stair assembly for a trailer,motor home or like vehicle. Unlike existing retractable stair assembliesthat are installed underneath the trailer, embodiments of thisdisclosure provide a retractable stair assembly that is installed withinan interior cavity in the trailer frame. In this position, theretractable stair assembly is protected from weather elements outsidethe trailer when it is stowed. In some embodiments, the retractablestair assembly is installed in a position in which the step platform canmove between its stowed and deployed positions linearly along the sameplane as the slide assembly without needing a lift mechanism to elevatethe step platform towards the floor level of the trailer. Instead, thestep platform could be substantially at floor level in the deployedposition without being elevated. This allows the length of the stepplatform to be adjusted based on how far the step assembly is extended.Additionally, the retractable stair assembly does not reduce clearanceunderneath the trailer similar to existing stair assemblies that areinstalled underneath the trailer.

FIG. 3 illustrates a trailer 100 with an example embodiment of aretractable stair assembly 102 in a deployed position according to anembodiment of this disclosure. In the embodiment shown, the retractablestair assembly 102 includes a step platform 104 and a plurality of steps106 transitioning between a floor level of the trailer 100 out a door108 and an egress surface 110, such as the ground. A slide assembly 112is configured to move the retractable stair assembly 102 between thedeployed position and stowed position. In the stowed position, theretractable stair assembly 102 is positioned within a cavity defined inthe trailer frame (FIG. 5). As shown, the top of the step platform 104is substantially at floor level of the trailer in the deployed positioneven though the step platform 104 is substantially coplanar with theslide assembly. No elevation of the step platform 104 is necessarybecause the retractable stair assembly 102 is installed at a higherelevation within the trailer frame. In the example shown, first guidebrackets 114 a, 114 b and second guide brackets 116 a, 116 b arepivotally connected to the step platform 104 and the plurality of steps106. This allows the plurality of steps 106 to pivot between a deployedposition in which the steps define a stairway and a position in whichthe longitudinal axis of the plurality of steps are axially aligned withthe longitudinal axis of the step platform 104 (FIG. 4C) to be movedinto a stowed position.

FIGS. 4A-4D show a progression of the retractable stair assembly 102from a stowed position (FIG. 4A) in which the retractable stair assembly102 is disposed within a cavity in the trailer frame to a deployedposition (FIG. 4D) in which the step platform 104 and the plurality ofsteps 106 form a stairway. Referring to FIG. 4A, the retractable stairassembly 102 is in a stowed position. The retractable stair assembly 102is disposed in an internal cavity within the trailer's frame 126 (FIG.5). As shown, there is a door 118 that moves between a closed positionand an open position. The door 118 helps protect the retractable stairassembly 102 from the elements when in the closed position. In the openposition, as shown, the retractable stair assembly 102 can be extendedto the deployed position through an opening 120. In some embodiments,the door 118 may include one or more locks 122 to secure the door 118.

To move the retractable stair assembly 102 from the stowed to deployedpositions, the retractable stair assembly 102 is initially pulled out ofthe opening 120. FIG. 4B shows the retractable stair assembly 102 as itis initially pulled out of the opening 120. The retractable stairassembly 102 is slidably movable out of the opening 120 via the slideassembly 112. Accordingly, a user would grasp the distal end of thebottom step 106 and pull to start sliding the retractable stair assembly102 out of the opening 120.

FIG. 4C shows the retractable stair assembly 102 after continuing toslide out of the opening 120. As shown, the step platform 104 and theplurality of steps 106 are axially aligned. The retractable stairassembly 102 will continue to slide out of the opening until the slideassembly 112 is fully extended. At that point, the retractable stairassembly 102 cannot extend any further out of the opening 120 and can belowered to the ground. As the retractable stair assembly 102 is lowered,the first guide bracket 114 a, 114 b and the second guide bracket 116 a,116 b will separate by gravity force so the steps 106 form into astairway in a deployed position as shown in FIG. 4D. As shown, the firstguide bracket 114 a, 114 b and second guide bracket 116 a, 116 b arepivotally connected to each step. The pivotal connection points 124 ofthe first guide bracket 114 a, 114 b and second guide bracket 116 a, 116b to each step 106 are spaced apart to move the steps 106 into astairway in the deployed position while also providing structuralrigidity to help support the weight of persons using the retractablestair assembly 102.

FIGS. 5-7 show the retractable stair assembly 102 installed in a trailerframe 126 with the trailer body removed to reveal the positioning of theretractable stair assembly 102 within the trailer frame. In theembodiment shown, the trailer frame 126 includes a frame platform 128that is a base platform extending the entire length of the trailer. Thetrailer frame 126 has a first structural beam 130 and a secondstructural beam 132 extending longitudinal along the sides of the frameplatform 128. The beams 130, 132 define an internal cavity 134 therebetween above the frame platform 128. The retractable stair assembly 102is installed in the internal cavity between the beams 130, 132. Inaddition to the retractable stair assembly 102, there are plumbing pipesand drains 136 extending into the internal cavity 134 in the embodimentshown. As shown, the breams 130, 132, and pipes and drains 136 extendbetween the platform 128 and a subfloor 137. The retractable stairassembly is dimensioned to fit between the platform 128 and subfloor137. In some cases, that envelope between the platform 128 and subfloor137 may be approximately 4 inches or 10.2 cm. By installing theretractable stair assembly 102 in the internal cavity 134, theretractable stair assembly 102 is protected from outside elements. Asshown, the retractable stair assembly 102 longitudinally extendstransversely between the beams 130, 132. In the embodiment shown, thereis an opening 138 defined in beam 130 through which the retractablestair assembly 102 extends. A diagrammatical representation of the priorart retractable stair assembly 10 is shown in FIG. 6 to illustrate theposition below the beam 130 where it is exposed to weather elements andvulnerable to damage; in contrast, the retractable stair assembly 102 ispositioned above the platform 126 where it is not exposed to outsideelements. Likewise, instead of being positioned below the beam 130 likethe retractable stair assembly 10, the retractable stair assembly 102extends through the beam 130.

As shown, the slide assembly 112 includes slide rails 140 a, 140 b oneach side of the step platform 104 and steps 106. The slide rails 140 a,140 b extend transversely between the beams 130, 132. In the embodimentshown, the slide rails 140 a and 140 b are attached to the beams 130,132. As shown, a bracket 144 and fasteners 146 connect the slide rails140 a, 140 b with the beams 130, 132. The step platform 104 and steps106 are slidably coupled with the slide rails 140 a, 140 b, such as withrollers, bearings or other like mechanism. This allows the step platform104 and steps 106 to slidably move along line 142 into and out of thetrailer frame 126. In some embodiments, a lock 146 can be provided tolock the position of the retractable stair assembly 102 with respect tothe trailer frame during transit of the trailer 100.

EXAMPLES

Illustrative examples of the trailer, retractable stair assembly, andmethod disclosed herein are provided below. An embodiment of thetrailer, retractable stair assembly, and method may include any one ormore, and any combination of, the examples described below.

Example 1 is a trailer with a retractable stair assembly. The trailerincludes a trailer frame with a frame platform and at least onestructural beam extending from the frame platform. The frame platformand the structural beam define an interior cavity. The trailer alsoincludes a retractable stair assembly movable between a stowed positionin which the retractable stair assembly is positioned within theinterior cavity of the trailer frame and a deployed position in whichthe retractable stair assembly extends out of the trailer frame toestablish a plurality of steps out of the trailer to an egress surface.

In Example 2, the subject matter of Example 1 is further configured suchthat in the stowed position, a longitudinal plane defined by theretractable stair assembly is substantially coplanar with a longitudinalplane defined by the structural beam.

In Example 3, the subject matter of Example 2 is further configured suchthat the structural beam defines an opening and the retractable stairassembly extends through the opening in the structural beam in thedeployed position.

In Example 4, the subject matter of Example 3 is further configured suchthat a longitudinal axis of the retractable stair assembly isapproximately perpendicular to a longitudinal axis of the structuralbeam.

In Example 5, the subject matter of Example 2 is further configured suchthat at least a portion of the retractable stair assembly is fixedlyconnected with the structural beam.

In Example 6, the subject matter of Example 1 is further configured suchthat the retractable stair assembly comprises a platform slideablyconnected with a slide assembly and the platform is slidable between thestowed position in which the platform is fully within the interiorcavity of the trailer frame and the deployed position in which theplatform at least partially extends out of the trailer frame.

In Example 7, the subject matter of Example 6 is further configured suchthat a longitudinal plane of the platform is substantially coplanar witha longitudinal plane of the slide assembly in the deployed position.

In Example 8, the subject matter of Example 7 is further configured suchthat the platform is movable between the stowed position and thedeployed position substantially along a single plane.

In Example 9, the subject matter of Example 1 is further configured suchthat the frame platform includes an interior side not exposed to weatherelements and an exterior side exposed to weather elements, wherein theretractable stair assembly extends from the interior side of the frameplatform.

In Example 10, the subject matter of Example 9 is further configured toinclude a subfloor spaced apart from the interior side of the frameplatform such that the interior cavity is defined between the subfloorand the frame platform, and the retractable stair assembly is disposedin the interior cavity between the subfloor and the frame platform inthe stowed position.

In Example 11, the subject matter of Example 10 is further configuredsuch that a longitudinal plane defined by the retractable stair assemblyintersects with a longitudinal axis of a plumbing pipe or drainextending between the frame platform and the subfloor.

Example 12 is a retractable stair assembly for a trailer having aninterior cavity defined by a trailer frame. The retractable stairassembly includes a slide assembly, a platform, and a plurality ofsteps. The platform is connected with the slide assembly such that theplatform is slidably movable between a stowed position and a deployedposition. The plurality of steps are operatively connected with theplatform. The platform moves between the stowed position and thedeployed position along a single plane.

In Example 13, the subject matter of Example 12 is further configuredsuch that a longitudinal plane of the platform is substantially coplanarwith a longitudinal plane of the slide assembly in the deployedposition.

In Example 14, the subject matter of Example 13 is further configuredsuch that at least a portion of the plurality of steps are pivotallyconnected with the platform.

In Example 15, the subject matter of Example 14 is further configuredsuch that the plurality of steps are pivotal about the platform to aposition coplanar with the longitudinal plane of the platform when theplatform is in the stowed position.

In Example 16, the subject matter of Example 12 is further configuredsuch that the slide assembly is mounted to the trailer frame within theinterior cavity.

In Example 17, the subject matter of Example 16 is further configuredsuch that the platform is configured to be received within the interiorcavity of the trailer frame in the stowed position.

Example 18 is a method of moving a retractable trailer stair assemblybetween a stowed position and a deployed position. The method includesthe steps of: (i) providing a retractable stair assembly in a stowedposition in which the retractable stair assembly is disposed within aninterior cavity of a trailer frame; (ii) moving the retractable stairassembly from the stowed position to a deployed position extending outof the trailer frame, wherein the retractable stair assembly includes aplatform and a plurality of steps configured to define a set of stepsout of a trailer to an egress surface in the deployed position. In someembodiments, the platform is linearly movable between the stowedposition and the deployed position.

In Example 19, the subject matter of Example 18 is further configuredsuch that the retractable stair assembly includes a slide assembly thatis slidably connected with the platform such that a longitudinal planeof the platform is substantially coplanar with a longitudinal plane ofthe slide assembly in the deployed position.

In Example 20, the subject matter of Example 18 is further configuredsuch that the platform is configured to move between the stowed positionand the deployed position along a single plane.

Although the present disclosure has been described with reference toparticular means, materials and embodiments, from the foregoingdescription, one skilled in the art can easily ascertain the essentialcharacteristics of the invention and various changes and modificationsmay be made to adapt the various uses and characteristics withoutdeparting from the spirit and scope of the invention.

What is claimed is:
 1. A method of moving a retractable trailer stairassembly between a stowed position and a deployed position, the methodcomprising the steps of: providing a trailer with a trailer frame and asubfloor, wherein the trailer frame includes a frame platform and atleast one structural beam extending along a longitudinal axis of theframe platform, wherein the at least one structural beam extendsupwardly from the frame platform and longitudinally along at least oneside of the frame platform between a front and a rear of the frameplatform, wherein the subfloor is spaced apart from the frame platform,and wherein an interior cavity is defined between the subfloor, theframe platform, and the at least one structural beam; providing aretractable stair assembly in a stowed position in which the retractablestair assembly is disposed at least partially within the interior cavitybetween the subfloor and the frame platform not exposed to weatherelements; and moving the retractable stair assembly from the stowedposition to a deployed position extending out of the trailer frame,wherein the retractable stair assembly includes a platform and aplurality of steps configured to define a set of steps out of thetrailer to an egress surface in the deployed position.
 2. The method ofclaim 1, wherein in the stowed position, a longitudinal plane defined bythe retractable stair assembly is substantially coplanar with alongitudinal plane defined by the structural beam.
 3. The method ofclaim 1, wherein the at least one structural beam is proximate aperiphery of the frame platform.
 4. The method of claim 1, wherein alongitudinal plane defined by the frame platform is approximatelyperpendicular to a longitudinal plane defined by the subfloor.
 5. Themethod of claim 1, wherein at least a portion of the retractable stairassembly is fixedly connected with the at least one structural beam. 6.The method of claim 1, wherein the retractable stair assembly comprisesa stair platform slideably connected with a slide assembly, wherein thestair platform is slidable between the stowed position in which thestair platform is fully within the interior cavity and the deployedposition in which the stair platform at least partially extends out ofthe interior cavity.
 7. The method of claim 6, wherein a longitudinalplane of the stair platform is substantially coplanar with alongitudinal plane of the slide assembly in the deployed position. 8.The method of claim 7, wherein the stair platform is movable between thestowed position and the deployed position substantially along a singleplane.
 9. The method of claim 6, further comprising the step of moving alock between a locked position and an unlocked position, wherein thelock in the locked position prevents the retractable stair assembly frommoving to the deployed position.
 10. The method of claim 9, wherein thelock in the locked position prevents the stair platform from moving withrespect to the slide assembly.
 11. The method of claim 1, wherein alongitudinal plane defined by the retractable stair assembly intersectswith a longitudinal axis of a plumbing pipe or drain extending betweenthe frame platform and the subfloor.
 12. The method of claim 1, furthercomprising the step of moving a door between (i) a closed position thatblocks the retractable stair assembly from moving to the deployedposition and (ii) an open position that allows the retractable stairassembly to move to the deployed position.
 13. The method of claim 12,wherein the door is configured to protect the interior cavity fromweather elements when the door is in the closed position.
 14. The methodof claim 13, further comprising the step of moving a lock between alocked position and an unlocked position, wherein the locked positionprevents the door from moving to the open position and the unlockedposition allows the door to move to the open position.